Hoisting apparatus for use at a manhole

ABSTRACT

A hoisting apparatus ( 10 ) for use at a manhole ( 1 ), comprising a supporting mast and a jib crane ( 14 ) connected at an angle to an upper end portion ( 16 ) of the supporting mast ( 12 ). The jib crane ( 14 ) has a front member ( 18 ) pointing upwardly and extending on one side of the supporting mast ( 12 ) and a rear member ( 20 ) having a rear end section ( 22 ) extending on another side of the supporting mast ( 12 ). A linking rod ( 24 ) is connecting the rear member of the jib crane ( 14 ) to the supporting mast ( 12 ). The apparatus further comprises a winch mechanism ( 30 ) mounted onto the jib crane ( 14 ) and having a cable ( 32 ) cooperating with the front member ( 18 ) of the jib crane ( 14 ) for hoisting an object from the manhole ( 1 ). In a preferred embodiment, the apparatus comprise a security fence ( 40 ) for surrounding at least partially the manhole ( 1 ) and preventing accidental entry therein, the supporting mast ( 12 ) being part of the fence.

FIELD OF THE INVENTION

The present invention relates generally to the field of hoistingapparatuses and rescue assemblies. More particularly, it concerns ahoisting apparatus for use at a manhole or any confined space entry forrescue purposes or simply for lowering and raising a person or an objectentering the hole.

BACKGROUND OF THE INVENTION

Manholes provide access to confined spaces or underground structuressuch as a sewer, boiler, drain or other similar structures. Often,people have to go into such confined spaces, with or without workingmaterial. They usually go into and come out of the manhole by means of along ladder and a protective fence is usually erected around the openingof the manhole in order to prevent people that may pass thereby fromfalling into the manhole.

People working in manholes occasionally get seriously injured and, as aresult thereof, require to be evacuated as quickly and as safely aspossible from the manhole in order to be attended by a professional,such as a doctor and the like. The above-mentioned type ofmanhole-ladder assembly does not enable to quickly, easily, and safelyevacuate an injured person from the manhole.

To that effect, tripod hoisting devices have already been developed forattaching a person entering a manhole so that he or she can be recoveredin the event of any difficulties. These hoisting devices are also usedfor lowering and raising the working material necessary for the personsworking in confined spaces. These tripod hoists are however cumbersomeand once installed over the manhole, they interfere with persons orequipment being passed over the manhole. Examples of these prior arttripod hoists are given in the following US patents: U.S. Pat. No.4,589,523; U.S. Pat. No. 4,660,679; U.S. Pat. No. 4,824,076.

Also known in the art are the hoisting apparatuses disclosed in U.S.Pat. No. 5,725,070 and U.S. Pat. No. 5,022,489 that are both designed tobe secured to a manhole guardrail. These apparatuses are however alsocumbersome and, as for the tripod hoists, they extend right over themanhole once installed, thereby interfering with persons or equipmentbeing passed over the manhole. They are thus not very practical for aneasy and rapid use.

There is also U.S. Pat. No. 4,838,439 which discloses a hoist apparatuscomprising a swivel arm connected to a base member mountable over amanhole. The swivel arm is composed of a vertical post portion and a jibportion. The jib portion is rigidly connected to the post portion andextends upwardly and outwardly therefrom at an angle to the horizontal.A winch is mounted to the post. One drawback with this hoist apparatusis that it is fragile and not suitable for hoisting very heavy personsor objects. It has been shown that the joint connecting the jib portionto the post is not sufficient to resist to the flexion caused by theload hanging at the extremity of the jib portion.

Thus, there is still a need for a hoisting apparatus which would beeasily and quickly mountable in the vicinity of a manhole while allowingalso to lift very heavy objects or persons without interfering withpersons or equipment being passed over the manhole.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a hoisting apparatusfor use at a manhole that satisfies the above-mentioned needs.

In accordance with the present invention, that object is achieved with ahoisting apparatus comprising a supporting mast and a jib craneconnected at an angle to an upper end portion of the supporting mast.The jib crane has a front member pointing upwardly and extending on oneside of the supporting mast and a rear member having a rear end sectionextending on another side of the supporting mast. The apparatus furthercomprises a linking rod having a first end connected to the rear endsection of the jib crane and a second end connected to the supportingmast. A winch mechanism is mounted onto the jib crane. The winchmechanism has a cable cooperating with the front member of the jib cranefor hoisting an object and/or a person from the manhole.

As can be appreciated, a hoisting apparatus according to the inventioncomprises very few elements, which makes it easy and quick to mount andfairly lightweight in order to facilitate transportation thereof, whilebeing structurally sound, in order to safely support and evacuate aperson from the manhole.

Also, such minimal amount of elements provide for an easy maintenanceand/or part replacement thereof.

In accordance with a preferred embodiment, the hoisting apparatuscomprises a security fence for surrounding at least partially themanhole and preventing accidental entry therein, the supporting mastbeing part of the fence.

The security fence which is preferably foldable comprises fence sectionshingedly connected to one another. Also preferably, the fence sectionsare composed of vertical posts joined together by framing members, thesupporting mast being one of the vertical posts.

In accordance with another preferred embodiment, the hoisting apparatuscomprises a base support for vertically mounting the mast. The basesupport preferably comprises a female connector for removably receivinga bottom end of the mast.

It is also an object of the present invention to provide a hoistingapparatus for use at a manhole, comprising a security fence forsurrounding at least partially the manhole and preventing accidentalentry therein, the fence comprising fence sections composed of verticalposts joined together by framing members. The hoisting apparatus ischaracterized in that it further comprises a hoisting mechanismmountable onto one of the vertical posts, hereinafter referred to as thesupporting mast, for hoisting an object from the manhole.

The hoisting mechanism preferably comprises a jib crane connected at anangle to an upper end portion of the supporting mast. The jib crane hasa front member pointing upwardly and extending on one side of thesupporting mast substantially over the manhole and a rear member havinga rear end section extending on another side of the supporting mast. Inthis case, the apparatus further comprises a linking rod having a firstend connected to the rear end section of the jib crane and a second endconnected to the supporting mast. A winch mechanism is mounted onto thejib crane. The winch mechanism has a cable cooperating with the frontmember of the jib crane for hoisting an object and/or a person from themanhole.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and advantages of the invention will becomeapparent upon reading the detailed description and upon referring to thedrawings in which:

FIG. 1 is a perspective view of a hoisting apparatus according to afirst preferred embodiment of the invention mounted in the vicinity of amanhole and showing a person being rescued with the apparatus.

FIG. 2 is a perspective exploded view of a variant of the hoistingapparatus shown in FIG. 1.

FIG. 3 is a perspective view of a hoisting apparatus according to asecond preferred embodiment of the invention mounted to a square-shapedmanhole.

FIG. 4 is a perspective view of a hoisting apparatus according to athird preferred embodiment of the invention mounted in the vicinity of around-shaped manhole.

FIG. 5 is a perspective view of a base support that can be used witheither one of the hoisting apparatuses shown in FIGS. 3 and 4.

FIG. 6 is a perspective view of another base that can be used witheither one of the hoisting apparatuses shown in FIGS. 3 and 4.

While the invention will be described in conjunction with exampleembodiments, it will be understood that it is not intended to limit thescope of the invention to such embodiments. On the contrary, it isintended to cover all alternatives, modifications and equivalents as maybe included as defined by the appended claims.

DESCRIPTION OF PREFERRED EMBODIMENTS

In the following description, similar features in the drawings have beengiven similar reference numerals and in order to lighten the figures,some elements are not referred to in some figures if they were alreadyidentified in a precedent figure.

Moreover, although the present invention was primarily designed forrescue purposes of individuals injured inside manholes so as to enableto evacuate them, it may be used for other applications and with otherobjects, such as a mining raise for example or for transportation ofmaterial, as apparent to a person skilled in the art. For this reason,the expressions “manhole”, “person” and “rescue” should not be taken asto limit the scope of the present invention and include all other kindsof objects and purposes with which the present invention could be usedand may be useful. For example, the expression “manhole” refers to anyhorizontally extending hole giving access to an underground confinedspace or structure such as a sewer, boiler, drain or other similarstructure.

Referring to either one of FIGS. 1, 3 and 4 and broadly described, thehoisting apparatus (10) according to the invention is suitable for useat a manhole (1) for raising and lowering objects and/or persons. It isthus very useful for rescuing purposes. The apparatus (10) comprises asupporting mast (12) and a jib crane (14) connected at an angle to anupper end portion (16) of the supporting mast (12). The jib crane (14)is composed of a front member (18) pointing upwardly and extending onone side of the supporting mast (12) and a rear member (20) having arear end section (22) extending on another side of the supporting mast(12). The jib crane (14) which is preferably removably mountable ontothe supporting mast (12) comprises a connector (23) on the rear member(20) adapted to removably receive the upper end of the supporting mast(12). The connector (23) may have the shape of a socket-type connectorwhich receives the upper end of the mast (12). A conventional pin (25)can be used to secure the parts together.

In order to solidify the structure and make it suitable for hoistingheavy objects, the apparatus (10) further comprises a linking rod (24)having a first end (26) connected to the rear end section (22) of therear member (20) of the jib crane (14) and a second end (28) connectedto the supporting mast (12), preferably near the bottom end thereof. Theapparatus (10) of the invention is preferably designed so as to enableto hoist an object or a person weighing up to about 300 pounds.

Preferably also, the first end (26) and the second end (28) of thelinking rod (24) are removably connected to the rear member (20) and thesupporting mast (12) respectively by means of pins (25).

A winch mechanism (30) is mounted onto the jib crane (14), preferably onthe rear member (20) thereof. The winch mechanism (30) has a cable (32)cooperating with the front member (18) of the jib crane (14) forhoisting an object and/or a person from the manhole (1).

The rear member (20) is preferably sleeve-shaped and adapted totelescopically receive the front member (18) of the jib crane (14),thereby making it easy to adjust the length of the front member (18).Obviously in such a case, the apparatus (10) is provided with suitablelocking means for removably locking the telescopic front member (18) indifferent positions. Suitable locking means are for example pins, screwsor the like.

Although the supporting mast (12) and the front member (18) preferablyhave a circular cross section and the rear member (20) preferably has asquare cross section as in the apparatuses illustrated, they may takeany other shape as apparent to any person skilled in the art. Forexample, the rear member (20) could also have a circular cross sectionor all these elements may have a square cross section.

As can be appreciated, when a person is suspended at the end of thecable (32), the supporting mast (12) is put under a compression forcewhile the linking rod (24) is put under a tension force. The load towhich the apparatus (10) is subjected in supporting the weight is thusefficiently distributed in the structure, making it possible to suspendvery heavy loads. The linking rod (24) thus helps reinforcing theresistance of the jib crane (14).

In accordance with a first preferred embodiment shown in FIGS. 1 and 2,the hoisting apparatus (10) comprises a security fence (40) forsurrounding at least partially the manhole (1) and preventing accidentalentry therein. As can be appreciated, the supporting mast (12) describedabove is one of the structural posts of the fence (40). In FIG. 1, thefence (40) is surrounding the manhole (1) partially, whereas the fence(40) shown in FIG. 2 encircles the manhole (1) completely. In bothcases, the security fence (40), which is preferably foldable, comprisesfence sections (42) hingedly connected to one another. The fencesections (42) are composed of vertical posts (44) joined together byframing members (46) such as horizontal rails and cross rails. It ishowever worth noting that any other type of framing members (46) such asboards and wires commonly used in the making of fences can be usedwithout departing from the scope of the invention. The fence sections(42) are hindgely connected, preferably by means of metal collars (48)or any other means known in the art suitable for hingedly connectingvertical posts. Preferably also, the hoist mechanism (30) is removablyconnected to the jib crane (14) by means of pins for quick, easy andsafe assembling and dismantling of the assembly. It is worth mentioninghere that the above-mentioned components may be connected to theirrespective counterparts by other suitable connecting means, such asfasteners, sliding locks, and the like.

Referring now to FIGS. 3 and 4 and in accordance with another preferredembodiment, the hoisting apparatus (10) can be used without a fence. Insuch a case, the apparatus (10) comprises a base support (50) forvertically mounting the support mast (12). The base support (50)preferably comprises a female connector for removably receiving a bottomend of the mast (12). The base support (50) can take different shapes.Four of these different shapes are shown in FIGS. 3 to 6. In FIG. 3, thebase support (50), which is adapted to be secured to a vertical wall(2), comprises a plate (52) and a tubular socket (54) sized to receivethe bottom end of the mast (12). The tubular socket (54) is connectedlongitudinally to the plate (52). In FIG. 4, the base support (50) isadapted to be secured to a horizontal wall (4). In this case, thetubular socket (54) is connected at right angle to the plate (52).

The base support (50) shown in FIG. 5 is particularly suitable to beembedded in a concrete floor. In this case, the base support (50) isprovided with an anchoring member (56) located under the tubular socket(54).

The base support (50) shown in FIG. 6 is adapted to be connected to therim bordering the manhole of a transformer. In this case, and once thebase support (50) is connected to the rim, the tubular socket (54) is inthe void.

The components of the fence (40) and of the hoisting mechanism (30) arepreferably made of suitable materials, as apparent to a person skilledin the art. Preferably, most of their components are made from amaterial selected from the group consisting of aluminum, stainlesssteel, acetal and aluminum composite.

As may now be appreciated, the present invention is an improvement andpresents several advantages over the prior art in that, as described andexplained herein, the hoisting apparatus (10) according to the presentinvention enables to quickly, easily, and safely evacuate an injuredperson from a manhole. Furthermore, the present invention is alsoadvantageous in that, by virtue of its design and components, it may beeasily and quickly mounted while allowing also to be easily dismantledfor proper storage. Furthermore, the present invention is alsoadvantageous in that its design enables it to be fairly lightweight,while being structurally sound in order to safely support and evacuate aperson from the manhole. Furthermore, the present invention is alsoadvantageous in that the interconnection of the components as describedherein enables for easy maintenance and/or part replacement of thehoisting apparatus (10).

In addition, although the preferred embodiment of the present inventionas illustrated in the accompanying drawings comprises various componentssuch as pins, sockets, rods, etc., and although the preferred embodimentof the rescue assembly as shown consists of certain geometricalconfigurations as explained and illustrated herein, not all of thesecomponents and geometries are essential to the invention and thus shouldnot be talken in their restrictive sense, i.e. should not be taken as tolimit the scope of the present invention. It is to be understood, asalso apparent to a person skilled in the art, that other suitablecomponents and cooperations thereinbetween, as well as other suitablegeometrical configurations, may be used for the fence and for thehoisting means of the rescue assembly according to the present inventionwithout departing from the scope of the present invention.

Although preferred embodiments of the present invention have beendescribed in detail herein and illustrated in the accompanying drawings,it is to be understood that the invention is not limited to theseprecise embodiments and that various changes and modifications may beeffected therein without departing from the scope or spirit of thepresent invention.

1. A hoisting apparatus for use at a manhole, comprising: a supporting mast; a jib crane connected at an angle to an upper end portion of the supporting mast, the jib crane having a front member pointing upwardly and extending on one side of the supporting mast and a rear member having a rear end section extending on another side of the supporting mast; a linking rod having a first end connected to said rear end section and a second end connected to the supporting mast; and a winch mechanism mounted onto the jib crane and having a cable cooperating with the front member of the jib crane for hoisting an object from the manhole.
 2. A hoisting apparatus according to claim 1, comprising a security fence for surrounding at least partially the manhole and preventing accidental entry therein, said supporting mast being part of said fence.
 3. A hoisting apparatus according to claim 2, wherein said security fence is foldable and comprises fence sections hingedly connected to one another.
 4. A hoisting apparatus according to claim 3, wherein said fence sections are composed of vertical posts joined together by framing members, the supporting mast being one of said vertical posts.
 5. A hoisting apparatus according to claim 4, wherein said framing members are rails.
 6. A hoisting apparatus according to claim 1, wherein the rear member is sleeve-shaped and the front member is telescopically mounted into the rear member.
 7. A hoisting apparatus according to claim 1, comprising a socket connector on the rear member for removably receiving the upper end of the supporting mast.
 8. A hoisting apparatus according to claim 1, comprising a base support for vertically mounting the mast.
 9. A hoisting apparatus according to claim 8, wherein the base support comprises a socket connector for removably receiving a bottom end of the mast.
 10. A hoisting apparatus according to claim 1, comprising pins for respectively and removably connecting the first end and the second end of the linking rod to the rear member and the supporting mast. 